Monday, 27 October 2014

Walking in a more happy style could help counter the negative mental processes associated with depression. That's according to psychologists in Germany and Canada who used biofeedback to influence the walking style of 47 university students on a treadmill.

The students, who were kept in the dark about the true aims of the study, had their gait monitored with motion capture technology. For half of them, the more happily they walked (characterised by larger arm and body swings, and a more upright posture), the further a gauge on a video monitor shifted to the right; the sadder their gait, the more it shifted leftwards. The students weren't told what the gauge measured, but they were instructed to experiment with different walking styles to try to shift the bar rightwards. This feedback had the effect of encouraging them to walk with a gait characteristic of people who are happy.

For the other half of the students, the gauge direction was reversed, and the sadder their gait, the further the gauge shifted to the right. Again, these students weren't told what the gauge measured, but they were instructed to experiment with their walking style and to try to shift the gauge rightwards as far as possible. In other words, the feedback encouraged them to adopt a style of walking characteristic of people who are feeling low.

After four minutes of gait feedback on the treadmill, both groups of students were asked how much forty different positive and negative emotional words were a good description of their own personality. This quiz took about two minutes, after which the students continued for another eight minutes trying to keep the gait feedback gauge deflected to the right. The students' final and crucial task on the treadmill was to recall as many of the earlier descriptive words as possible.

The striking finding is that the students who were unknowingly guided by feedback to walk with a happier gait tended to remember more positive than negative self-referential words, as compared with the students who were guided to walk with a more negative style. That is, the happy walkers recalled an average of 6 positive words and 3.8 negative words, compared with the sad walkers who recalled an average of 5.47 positive words and 5.63 negative words. Focusing on the students who achieved the happiest style of gait, they recalled three times as many positive words as the students who achieved the saddest style of gait.

"Our results show that biased memory towards self-referent negative material [a feature of depression] can be changed by manipulating the style of walking," said the research team led by Johannes Michalak. The observed effects of gait on memory were not accompanied by any group differences in the students' self-reported mood at the end of the study, suggesting a direct effect of walking style on emotional memory processes.

The results build on past research that suggests pulling a happy facial expression can lift people's mood. There could be exciting practical implications for helping people with depression, but the researchers acknowledged some issues need to be addressed. For example, the current study involved a small non-clinical sample, and the researcher who delivered the forty emotional words to the walking students was not blind to the gait condition they were in, raising the possibility that he or she inadvertently influenced the results in some way. It's also notable that there wasn't data from a baseline control group whose gait was not influenced; it would have been useful to see how they performed on the memory test.
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